It's somewhat considered to be a bad practice to limit the length of the password or use a low (<64 characters) length value. After reading all the great reviews I was a little disappointed that a security service doesn't allow me to use a password I consider secure (without being too paranoid). Can I wonder what's the reason behind the restriction?

Thank you for the feedback. Currently, the primary reason for the password length limit is due to the restrictions of PPTP and L2TP with utilizing max 14 character passwords. OpenVPN supports longer passwords, but this would cause issues when a user would want to use PPTP or L2TP (including connections from the Vypr iOS app). The idea has been discussed to try engineering a solution for the PPTP/L2TP protocols.